Batt insulation for bonus room... installed correctly?

ok. I live in the South (Lower Alabama) and my bonus room above my garage, gets warm during the summer. I went in the attic today to see how the insulation was installed and I noticed that it is Paper towards the room (insulation towards the hot attic space). I read a few articles where basically is states that it doesn't matter (or depends) on which way the paper faces.

The biggest issue I have is that the insulation is extending past the joists into the attic space. I also think that the paper is not installed up against the drywall of the bonus room. Do either or both of these issues matter? Would it be better if I turn all the insulation around and staple it back to the joists to ensure that it stays flush with the joist to ensure a tight fit. Right now I don't think there is a tight fit because the insulation does extend past the joists into the attic.

2 Answers

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1.

Nathan,
You are probably right in your hunch that your insulation was not installed correctly.

First of all, fiberglass batts are the worst-performing insulation material available. Most fiberglass batts are poorly installed. To learn more, see Installing Fiberglass Right.

To answer a few of your questions:
1. It doesn't really matter which way the kraft facing is installed in your climate.
2. Any insulation (but especially fiberglass) should be installed so that it touches the drywall, without an air space between the drywall and the insulation.

The main problem with fiberglass batts is that they are usually installed with no attention to airtightness. Especially when it comes to bonus rooms, the installer has to have a clear understanding of where the air barrier is, and has to pay a considerable amount of attention to sealing all penetrations and transitions from ceiling to wall to floor, to make sure that there are no air leaks. A common problem, for example, is a lack of blocking between the floor joists in a location where blocking is warranted.

Finally, it should be pointed out that the best insulation above a horizontal drywall ceiling is usually cellulose. To do it right, (a) seal all air leaks, and (b) install a thick layer of cellulose.